<template>
  <!-- 城市选择-->
  <view class="city-select">
    <scroll-view :scroll-top="scrollTop" scroll-y="true" class="city-select-main" id="city-select-main" :scroll-into-view="toView">
      <!-- 预留搜索-->
      <!-- <view class="city-serach" v-if="isSearch"><input @input="keyInput" :placeholder="placeholder" class="city-serach-input" /></view> -->
      <!-- 当前定位城市 -->
      <view class="hot-title" v-if="activeCity && !serachCity">定位/最近访问</view>
      <view class="hot-city" v-if="activeCity && !serachCity">
        <view class="hot-item" @click="cityTrigger(activeCity)">
          <van-icon v-if="activeCity[formatName] == '定位失败'" style="margin-right: 4px" name="replay" size="18" color="#4f4f4f" />
          <van-icon v-else name="location" size="20" style="margin-right: 4px" color="red" />
          {{ activeCity[formatName].length >= 4 ? activeCity[formatName].substring(0, 4) + '...' : activeCity[formatName] }}
        </view>
        <view class="hot-item" v-for="history in historyCity" :key="history.cityCode" @click="cityTrigger(history)">{{
          history.cityName.length >= 5 ? history.cityName.substring(0, 5) + '...' : history.cityName
        }}</view>
      </view>
      <!-- 热门城市 -->
      <view class="hot-title" v-if="hotCity.length > 0 && !serachCity">热门城市</view>
      <view class="hot-city hotCity" v-if="hotCity.length > 0 && !serachCity">
        <template v-for="(item, index) in hotCity">
          <view :key="index" @click="cityTrigger(item, 'hot')" class="hot-item">{{ item[formatName] }}</view>
        </template>
      </view>
      <!-- 城市列表(搜索前) -->
      <view class="citys" v-if="!serachCity">
        <view v-for="(city, index) in sortItems" :key="index" v-show="city.isCity" class="citys-row">
          <view class="citys-item-letter" :id="'city-letter-' + (city.name === '#' ? '0' : city.name)">{{ city.name + ` &nbsp;&nbsp;` + '——————————————————' }}</view>
          <view class="citys-item" v-for="(item, inx) in city.citys" :key="inx" @click="cityTrigger(item)">{{ item.cityName }}</view>
        </view>
      </view>
      <!-- 城市列表(搜索后)  -->
      <view class="citys" v-if="serachCity">
        <view v-for="(item, index) in searchDatas" :key="index" class="citys-row">
          <view class="citys-item" :key="inx" @click="cityTrigger(item)">{{ item.name }}</view>
        </view>
      </view>
    </scroll-view>
    <!-- 城市选择索引-->
    <view class="city-indexs-view" v-if="!serachCity">
      <view class="city-indexs">
        <view v-for="(cityIns, index) in handleCity" class="city-indexs-text" v-show="cityIns.isCity" :key="index" @click="cityindex(cityIns.forName)">
          {{ cityIns.name }}
        </view>
      </view>
    </view>
  </view>
</template>

<script>
import citys from './citys.js'
import citySelect from './citySelect.js'
export default {
  props: {
    // 查询提示文字
    placeholder: {
      type: String,
      default: '请输入城市名称'
    },
    // 传入要排序的名称
    formatName: {
      type: String,
      default: 'cityName'
    },
    // 当前定位城市
    activeCity: {
      type: Object,
      default: () => null
    },
    // 热门城市
    hotCity: {
      type: Array,
      default: () => []
    },
    // 城市数据
    // obtainCitys: {
    // 	type: Array,
    // 	default: () => []
    // },
    historyCity: {
      type: Array,
      default: () => []
    },
    // 是否有搜索
    isSearch: {
      type: Boolean,
      default: true
    }
  },
  data() {
    return {
      toView: 'city-letter-Find', // 锚链接 初始值
      scrollTop: 0, // scroll-view 滑动的距离
      cityindexs: [], // 城市索引
      activeCityIndex: '', // 当前所在的城市索引
      handleCity: [], // 处理后的城市数据
      serachCity: '', // 搜索的城市
      cityData: []
      // obtainCitys:[]
    }
  },
  computed: {
    /**
     * @desc 城市列表排序
     * @return  Array
     */
    sortItems() {
      for (let index = 0; index < this.handleCity.length; index++) {
        if (this.handleCity[index].isCity) {
          let cityArr = this.handleCity[index].citys
          cityArr = cityArr.sort(function (a, b) {
            const value1 = a.unicode
            const value2 = b.unicode
            return value1 - value2
          })
        }
      }
      return this.handleCity
    },
    /**
     * @desc 搜索后的城市列表
     * @return Array
     */
    searchDatas() {
      const searchData = []
      for (let i = 0; i < this.cityData.length; i++) {
        if (this.cityData[i][this.formatName].indexOf(this.serachCity) !== -1) {
          searchData.push({
            oldData: this.cityData[i],
            name: this.cityData[i][this.formatName]
          })
        }
      }
      return searchData
    }
  },
  created() {
    // 初始化城市数据
    this.cityData = citys
    this.initializationCity()
    this.buildCityindexs()
  },
  // watch: {
  // 	obtainCitys(newData) {
  // 		this.updateCitys(newData);
  // 	}
  // },
  methods: {
    /**
     * @desc 初始化
     */
    // updateCitys(data) {
    // 	if (data && data.length) {
    // 		this.cityData = data;
    // 		this.initializationCity();
    // 		this.buildCityindexs();
    // 	}
    // },
    /**
     * @desc 监听输入框的值
     */
    keyInput(event) {
      this.serachCity = event.detail.value
    },
    /**
     * @desc 初始化城市数据
     * @return undefind
     */
    initializationCity() {
      this.handleCity = []
      const cityLetterArr = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '#']
      for (let index = 0; index < cityLetterArr.length; index++) {
        this.handleCity.push({
          name: cityLetterArr[index],
          isCity: false, // 用于区分是否含有当前字母开头的城市
          citys: [], // 存放城市首字母含是此字母的数组
          forName: 'city-letter-' + (cityLetterArr[index] === '#' ? '0' : cityLetterArr[index]) // label的绑定
        })
      }
    },
    /**
     * @desc 得到城市的首字母
     * @param str String
     */
    getLetter(str) {
      return citySelect.getFirstLetter(str[0])
    },
    /**
     * @desc 构建城市索引
     * @return undefind
     */
    buildCityindexs() {
      this.cityindexs = []
      for (let i = 0; i < this.cityData.length; i++) {
        // 获取首字母
        const cityLetter = this.getLetter(this.cityData[i][this.formatName]).firstletter
        // 获取当前城市首字母的unicode，用作后续排序
        const unicode = this.getLetter(this.cityData[i][this.formatName]).unicode

        const index = this.cityIndexPosition(cityLetter)
        if (this.cityindexs.indexOf(cityLetter) === -1) {
          this.handleCity[index].isCity = true
          this.cityindexs.push(cityLetter)
        }

        this.handleCity[index].citys.push({
          cityName: this.cityData[i][this.formatName],
          unicode: unicode,
          oldData: this.cityData[i]
        })
      }
    },
    /**
     * @desc 滑动到城市索引所在的地方
     * @param id String 城市索引
     */
    cityindex(id) {
      this.toView = id
      // //创建节点查询器
      // const query = uni.createSelectorQuery().in(this)
      // var that = this
      // that.scrollTop = 0
      // //滑动到指定位置(解决方法:重置到顶部，重新计算，影响:页面会闪一下)
      // setTimeout(() => {
      // 	query
      // 		.select('#city-letter-' + (id === '#' ? '0' : id))
      // 		.boundingClientRect(data => {
      // 			// console.log("得到布局位置信息" + JSON.stringify(data));
      // 			// console.log("节点离页面顶部的距离为" + data.top);
      // 			data ? (that.scrollTop = data.top) : void 0
      // 		})
      // 		.exec()
      // }, 0)
    },
    /**
     * @desc 获取城市首字母的unicode
     * @param letter String 城市索引
     */
    cityIndexPosition(letter) {
      if (!letter) {
        return ''
      }
      const ACode = 65
      return letter === '#' ? 26 : letter.charCodeAt(0) - ACode
    },
    /** @desc 城市列表点击事件
     *  @param Object
     */
    cityTrigger(item) {
      // 传值到父组件
      this.$emit('cityClick', item.oldData ? item.oldData : item)
    }
  }
}
</script>

<style lang="scss">
//宽度转换vw
@function vww($number) {
  @return ($number / 375) * 750 + rpx;
}

view {
  box-sizing: border-box;
}

.city-serach {
  width: 100%;
  color: #4a4a4a;
  padding: 0 vww(10);

  &-input {
    margin: vww(10) 0;
    height: vww(40);
    line-height: vww(40);
    font-size: vww(14);
    padding: 0 vww(5);
    border: 1px solid #4d8cfd;
    border-radius: 3px;
  }
}

.city-select-main {
  position: relative;
  // overflow: scroll;
  // -webkit-overflow-scrolling: touch;
  width: 100%;
  height: 100%;
  background: #ffffff;
  // overflow-y: auto;
}

.city-select {
  position: relative;
  width: 100vw;
  height: 100vh;
  background: #f6f5fa;

  // 热门城市
  .hot-title {
    padding-left: vww(23);
    width: 100vw;
    font-size: 14px;
    line-height: vww(40);
    color: #000000;
    padding-top: 5px;
    padding-bottom: 5px;
  }

  .hotCity {
    margin-bottom: 10px;
  }

  .hot-city {
    padding-left: vww(23);
    padding-right: vww(20);
    overflow: hidden;
    width: 100vw;

    .hot-item {
      float: left;
      margin-right: vww(16);
      margin-bottom: vww(6);
      overflow: hidden;
      width: vww(100);
      height: vww(31);
      font-size: 14px;
      text-align: center;
      display: flex;
      justify-content: center;
      align-items: center;
      line-height: vww(31);
      border: 1px solid #ebebf0;
      background: #f2f2f2;
      border-radius: 4px;
      font-weight: 500;
      color: #000000;

      &:nth-child(3n) {
        margin-right: 0;
      }
    }

    .hot-hidden {
      display: none;
      margin-right: 0;
    }
  }

  .citys {
    .citys-row {
      padding-left: vww(18);
      width: 100%;
      font-size: 14px;
      background: #fff;

      .citys-item-letter {
        margin-left: vww(-18);
        padding-left: vww(18);
        margin-top: -1px;
        width: 100vw;
        font-size: 16px;
        line-height: vww(30);
        color: #cccccc;
        background: #ffffff;
        border-top: none;
      }

      .citys-item {
        width: 100%;
        line-height: vww(50);
        color: #000000;
      }
    }
  }

  .city-indexs-view {
    position: absolute;
    right: 0;
    bottom: 0;
    z-index: 999;
    display: flex;
    width: vww(20);
    height: 100%;
    text-align: center;
    align-items: flex-end;

    .city-indexs {
      width: vww(20);
      text-align: center;
      vertical-align: middle;
      margin-bottom: 5px;

      .city-indexs-text {
        margin-bottom: vww(5);
        width: vww(20);
        font-size: 12px;
        color: #cccccc;

        &:last-child {
          margin-bottom: 0;
        }
      }
    }
  }
}
</style>
